title: The effect of carbidopa and benserazide on human plasma 5-hydroxytryptophan levels.
abstract: Peripheral aromatic amino acid decarboxylase inhibitors increase human plasma 5-hydroxytryptophan (5-HTP) levels. However the 5-HTP, which is synthesized in the intestine, is not present in a sufficient quantity to influence brain 5-HT to any significant degree. Thus, peripheral decarboxylase inhibitors are unlikely to affect brain 5-HT function via 5-HTP which is synthesized peripherally.
mesh_terms: D006916:5-Hydroxytryptophan / Q000097:blood*; D000328:Adult; D001545:Benserazide / Q000627:therapeutic use*; D002230:Carbidopa / Q000627:therapeutic use*; D002746:Chlorpromazine / Q000627:therapeutic use; D004295:Dihydroxyphenylalanine / Q000627:therapeutic use; D006801:Humans; D006834:Hydrazines / Q000627:therapeutic use*; D008875:Middle Aged; D010300:Parkinson Disease / Q000097:blood / Q000188:drug therapy; D012559:Schizophrenia / Q000097:blood / Q000188:drug therapy; D014364:Tryptophan / Q000627:therapeutic use
chemical_list: D006834:Hydrazines; D004295:Dihydroxyphenylalanine; D001545:Benserazide; D014364:Tryptophan; D006916:5-Hydroxytryptophan; D002230:Carbidopa; D002746:Chlorpromazine